Glaucoma in China: how big is the problem?

Aims-To derive preliminary estimates for the number of adults in China suff ering from glaucoma, and project the burden of visual morbidity attributabl e to primary and secondary glaucoma. Methods-Age and sex specific data from two population surveys were applied to US Census Bureau population estimates for urban and rural China. It was assumed that data from Singapore were representative of urban China, and th ose from Mongolia were representative of rural China. Results-It was estimated that 9.4 million people aged 40 years and older in China have glaucomatous optic neuropathy. Of this number, 5.2 million (55% ) are blind in at least one eye and 1.7 million (18.1%) are blind in both e yes. Primary angle closure glaucoma (PACG) is responsible for the vast majo rity (91%) of bilateral glaucoma blindness in China. The number of people w ith the anatomical trait predisposing to PACG (an "occludable" drainage ang le) is in the region of 28.2 million, and of these 9.1 million have signifi cant angle closure, indicated by peripheral anterior synechiae or raised in traocular pressure. Conclusions-This extrapolation of data from two east Asian countries gives an approximate number of people in China suffering from glaucoma. It is unl ikely that this crude statistical model is entirely accurate. However, the authors believe the visual morbidity from glaucoma in China is considerable . PACG is probably the leading cause of glaucoma blindness in both eyes, an d warrants detailed investigation of strategies for prevention.